linux内核驱动实现led灯点亮

#include 
#include 
#include 
#include 
#include 
#include "head.h"

//定义变量存放映射的虚拟地址
//LED1
unsigned int *vir_moder;
unsigned int *vir_odr;
unsigned int *vir_rcc;

//LED2
unsigned int *vir_led2_moder;
unsigned int *vir_led2_odr;
unsigned int *vir_led2_rcc;

//LED3
unsigned int *vir_led3_moder;
unsigned int *vir_led3_odr;
unsigned int *vir_led3_rcc;

int major;
char kbuf[128]={0};
int mycdev_open(struct inode *inode, struct file *file)
{
    printk("%s:%s:%d\n", __FILE__, __func__, __LINE__);
    return 0;
}

ssize_t mycdev_read(struct file *file, char *ubuf, size_t size, loff_t *off)
{
    int ret;
    if(size>sizeof(kbuf))       //size传过来的是sizeof(ubuf),如果ubuf>kbuf,那么实际长度为kbuf
        size = sizeof(kbuf);
    ret = copy_to_user(ubuf, kbuf, size);
    if(ret)
    {
        printk("copy to user failed...\n");
        return -EIO;
    }
    printk("%s:%s:%d\n", __FILE__, __func__, __LINE__);
    return 0;
}

ssize_t mycdev_write(struct file *file, const char *ubuf, size_t size, loff_t *off)
{
    int ret;
    if(size>sizeof(kbuf))
        size = sizeof(kbuf);
    ret = copy_from_user(kbuf, ubuf, size);
    if(ret)
    {
        printk("copy from user failed...\n");
        return -EIO;
    }

    switch(kbuf[0])
    {
        case '0':
            (*vir_odr) &= (~(1 << 10));
            break;
        case '1':
            (*vir_odr) |= (1 << 10);
            break;
        case '2':
            (*vir_led2_odr) &= (~(1 << 10));
            break;
        case '3':
            (*vir_led2_odr) |= (1 << 10);
            break;
        case '4':
            (*vir_led3_odr) &= (~(1 << 8));
            break;
        case '5':
            (*vir_led3_odr) |= (1 << 8);
            break;
    }
    /*
    if(kbuf[0] == '1')
        (*vir_odr) |= (1 << 10);  //亮
    else if(kbuf[0] == '0')
        (*vir_odr) &= (~(1 << 10));   //灭
    */
    return 0;
}

int mycdev_close(struct inode *inode, struct file *file)
{
    printk("%s:%s:%d\n", __FILE__, __func__, __LINE__);
    return 0;
}

struct file_operations fops=
{
    .open = mycdev_open,
    .read = mycdev_read,
    .write = mycdev_write,
    .release = mycdev_close,
};


//入口
static int __init mycdev_init(void)
{
    major = register_chrdev(0, "mycdev", &fops);
    if(major<0)
    {
        printk("字符设备驱动注册失败\n");
        return major;
    }
    printk("字符设备驱动注册成功,major=%d\n", major);

    //物理地址的映射
    //LED1
    vir_moder = ioremap(PHY_LED1_MODER, 4);
    if(vir_moder == NULL)
    {
        printk("LED1_MODER寄存器映射失败...\n");
        return -ENOMEM;
    }
    vir_odr = ioremap(PHY_LED1_ODR, 4);
    if(vir_odr == NULL)
    {
        printk("LED1_ODR寄存器映射失败...\n");
        return -ENOMEM;
    }
    vir_rcc = ioremap(PHY_LED1_RCC, 4);
    if(vir_rcc == NULL)
    {
        printk("LED1_RCC寄存器映射失败...\n");
        return -ENOMEM;
    }

    //LED2
    vir_led2_moder = ioremap(PHY_LED2_MODER, 4);
    if(vir_led2_moder == NULL)
    {
        printk("LED2_MODER寄存器映射失败...\n");
        return -ENOMEM;
    }
    vir_led2_odr = ioremap(PHY_LED2_ODR, 4);
    if(vir_led2_odr == NULL)
    {
        printk("LED2_ODR寄存器映射失败...\n");
        return -ENOMEM;
    }
    vir_led2_rcc = ioremap(PHY_LED1_RCC, 4);
    if(vir_led2_rcc == NULL)
    {
        printk("LED2_RCC寄存器映射失败...\n");
        return -ENOMEM;
    }

    printk("LED2寄存器初始化成功...\n");

    //LED3
    vir_led3_moder = ioremap(PHY_LED1_MODER, 4);
    if(vir_led3_moder == NULL)
    {
        printk("LED3_MODER寄存器映射失败...\n");
        return -ENOMEM;
    }
    vir_led3_odr = ioremap(PHY_LED1_ODR, 4);
    if(vir_led3_odr == NULL)
    {
        printk("LED3_ODR寄存器映射失败...\n");
        return -ENOMEM;
    }
    vir_led3_rcc = ioremap(PHY_LED1_RCC, 4);
    if(vir_led3_rcc == NULL)
    {
        printk("LED3_RCC寄存器映射失败...\n");
        return -ENOMEM;
    }

    printk("物理地址映射成功...\n");

    //初始化LED1寄存器
    (*vir_moder) &= (~(3 << 20));
    (*vir_moder) |= (1 << 20);    //设置为输出模式
    (*vir_rcc) |= (1 << 4);   //rcc使能
    (*vir_odr) &= (~(1 << 10));   //低电平，灭
    printk("LED1寄存器初始化成功...\n");
    //初始化LED2寄存器
    (*vir_led2_moder) &= (~(3 << 20));
    (*vir_led2_moder) |= (1 << 20);    //设置为输出模式
    (*vir_led2_rcc) |= (1 << 5);   //rcc使能
    (*vir_led2_odr) &= (~(1 << 10));   //低电平，灭
    //初始化LED3寄存器
    (*vir_led3_moder) &= (~(3 << 16));
    (*vir_led3_moder) |= (1 << 16);    //设置为输出模式
    (*vir_led3_rcc) |= (1 << 4);   //rcc使能
    (*vir_led3_odr) &= (~(1 << 8));   //低电平，灭
    printk("LED3寄存器初始化成功...\n");
    
    return 0;
}

static void __exit mycdev_exit(void)
{
    iounmap(vir_moder);
    iounmap(vir_odr);
    iounmap(vir_rcc);
    iounmap(vir_led2_moder);
    iounmap(vir_led2_odr);
    iounmap(vir_led2_rcc);
    iounmap(vir_led3_moder);
    iounmap(vir_led3_odr);
    iounmap(vir_led3_rcc);
    unregister_chrdev(major, "mycdev");
}

module_init(mycdev_init);
module_exit(mycdev_exit);
MODULE_LICENSE("GPL");

#ifndef __HEAD_H__
#define __HEAD_H__

#define PHY_LED1_MODER 0x50006000
#define PHY_LED1_ODR 0x50006014
#define PHY_LED1_RCC 0x50000A28
#define PHY_LED2_ODR 0x50007014
#define PHY_LED2_MODER 0x50007000

#endif

#include 
#include 
#include 
#include 
#include 
#include 
#include 
int main(int argc, const char *argv[])
{
	char buf[128]={0};
	int fd = open("/dev/mycdev", O_RDWR);
	if(fd<0)
	{
		printf("error...\n");
		exit(-1);
	}
	while(1)
	{
		printf("请输入:关灯(0), 开灯(1)...");
		fgets(buf, sizeof(buf), stdin);
		buf[strlen(buf)-1] = '\0';
		write(fd, buf, sizeof(buf));
	}
	close(fd);
	return 0;
}